Below diagram is the set up which I am currently trying but doesn't work. My goal here is:
- Both TV Box and PC are under the same subnet 192.168.1.0/24
- Since Router 2 is a SIP client which connected to a desktop phone, it will need access to Internet.
- I need my VPN server working so that I can connect to my home using VPN from my PC or smartphone.
- I could add a switch and make Router 2 a SIP-to-RJ11 convertor only to solve this, but I don't want to do that unless I have no other choice.
Now my problem is: Everything is working now, except the desktop phone doesn't work.
Some information and limitation:
- Router 1 is Synology rt1900ac.
- Router 2 is a router provided from service provider. I only have access to some of the settings, but it is possible to request the service provider to change the other settings for us.
- Router 2 WAN port is configured to connect using DHCP. The service provider claimed that there is no "bridge" connection on WAN port.
- DHCP server on Router 2 is disabled.
- There is a wall between Router 1 and Router 2.
- I can see from Router 1 that Router 2 WAN port seems assigned to 192.168.1.2 using static DHCP from Router 1 but I have no way to verify it, because echo reply seems blocked on Router 2 WAN port.
- I have requested to disable NAT on Router 2, and seems it is disabled right now because I cannot ping to Internet when I set the PC to 172.16.1.11.
- Port forwarding for SIP (TCP/UDP 5060) has been configured on Router 1 to 192.168.1.2.
- Desktop phone is working fine, if I connect Router 1 LAN port to Router 2 WAN port.
So my question is, what options I have in order to achieve my goal?